JPH058026Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application] The present invention positions the workpiece in a predetermined position when screwing a screw into a pilot hole of a workpiece using a stationary screw tightening machine, and also locks the tip of the screw leg. This invention relates to a workpiece positioning device that reliably guides a workpiece into a pilot hole of a workpiece.

[Conventional technology]

Conventionally, when screwing a screw into a pilot hole on a workpiece using a stationary screw tightening machine, a workpiece positioning device was used to position the workpiece on the workbench and guide the screw at the tip of the driver bit into the pilot hole. has been done. This work positioning device 15
As shown in FIG.
A pilot pin 18 is housed in. This pilot pin 18 has a flange 18b at the lower end,
Furthermore, one end of a spring 19 housed in the stepped hole 17a is in contact with this flange portion 18b, so that the pilot pin 18 is urged upward and can be lowered.

[Problem that the invention attempts to solve]

In this workpiece positioning device 15, when a driver bit (not shown) located above it descends together with a screw (not shown) at its tip, the tip of the leg of the screw comes into contact with the pilot pin 18, and the pilot pin 18 descend. This pilot pin 1
As the driver bit 8 descends, the tip of the leg of the screw is guided into the prepared hole of the workpiece 14, so that the leg of the screw is reliably screwed into the workpiece 14 as the driver bit rotates. At this time, if the screw is a tapping screw, chips are generated during forming the female thread and fall onto the workbench 17. Therefore, these chips may get stuck in the gap between the workbench 17 and the pilot pin 18, and the next time the screws are tightened,
The pilot pin 18 no longer descends, and the screws are not guided into the pilot holes of the workpiece 14, resulting in disadvantages such as the inability to perform the prescribed screw tightening work.

[Means for solving problems]

The present invention aims to eliminate the above-mentioned drawbacks, and includes a driver stand that moves forward together with the operation of a cylinder, a motor fixed to the driver stand, and a motor that is movable up and down together with the driver stand and that receives the rotation of the motor. A stationary screw tightening machine having a screwdriver bit that rotates with a screwdriver is disposed. A workbench is fixed below the driver bit, and a pilot pin is disposed on the workbench so as to be aligned with the axis of the driver bit. This pilot pin is biased upward by a spring and configured to be retractable.

Further, a cover plate having a first loose insertion hole into which the pilot pin can be loosely inserted is fixed to the upper surface of the workbench, and a communication groove communicating with the first loose insertion hole is provided on the lower surface of the cover plate. It has been removed. On the other hand, an air hole is formed in the workbench so as to communicate with the communication groove, and an air control circuit is connected to the air hole so that air is supplied from an air supply source.

[Effect]

When the driver bit of a stationary screw tightening machine is lowered by the operation of the cylinder, the screw at the tip of the screw lowers and comes into contact with a pilot pin located through a prepared hole in a desired workpiece. As the pilot pin descends into the workbench, the screw is guided into the pilot hole of the workpiece and is securely screwed into the workpiece as the driver bit rotates.

Even if chips are generated when the screw is screwed into the workpiece, the air supplied through the air hole and communication groove blows up from the gap between the first loose insertion hole of the cover plate and the pilot pin. Therefore, this gap will not be clogged with chips. Therefore, the next time the screw is tightened, the pilot pin will reliably rise and return to the specified position, and then be reliably lowered into the workbench, guiding the screw into the pilot hole of the workpiece and screwing it into the workpiece. can do.

〔Example〕

Examples will be described below with reference to the drawings. In FIGS. 1 to 3, reference numeral 1 denotes a stationary screw tightening machine, which has a bracket 3 fixed to a column 2. In FIGS. This bracket 3 is connected to two parts via an arm part 4.
A book guide shaft 5 is guided in parallel so as to be freely raised and lowered. A driver's stand 6 is locked to the lower end of the guide shaft 5, and a driver's stand 7 is slidably held above it at a predetermined interval. A rod 8a of a cylinder 8 fixed to the upper end of the arm portion 4 is connected to the driver stand 7, and its operation causes the driver stand 7 and the chuck stand 6 to move together, and the chuck stand 6 to be attached to the stopper 9. After making contact with the driver stand 7, the driver stand 7 is configured to descend by itself. The driver stand 7
A motor 10 is fixed to the drive shaft 1.
A driver bit 12 is connected to 0a via a rotation transmission mechanism 11. This driver bit 1
2 passes through the chuck unit 13 fixed to the chuck base 6, and is located above the screw A held by the chuck pawl 13a rotatably attached to the chuck unit 13, and by its descent, screw A is held by the chuck pawl 13a. It is configured to be detached from the workpiece 14 and screwed into a prepared hole of a predetermined workpiece 14.

On the other hand, a table 16 of a workpiece positioning device 15 is arranged below the driver bit 12 of the stationary screw tightening machine 1, and a workbench 17 is fixed to this table 16. This workbench 17
A stepped hole 17a having the same center as the axis of the driver bit 12 is bored in the stepped hole 17a, and the stepped hole 17a has a flange portion 18b at the lower end and a small diameter portion 18a at the upper end. A pilot pin 18 is housed. This pilot pin 1
One end of a spring 19 housed in the stepped hole 17a is in contact with the lower surface of the flange 18b of No. 8, and constantly biases the pilot pin 18 upward. The pilot pin 18 is configured to descend as the leg portion of the pilot pin 18 comes into contact with the pilot pin 18. In addition, the workbench 1
7 is a hit pin 20 that determines the height of the workpiece 14
is installed parallel to the pilot pin 18, and the workpiece 14 is held at a predetermined height by the contact pin 20. Furthermore, a cover plate 2 is provided on the upper surface of the workbench 17.
1 is fixed, and the cover plate 21 is provided with a first loose insertion hole 21a and a second loose insertion hole 21b into which the pilot pin 18 and the abutting pin 20 can be loosely inserted, respectively. A pin 20 is configured to protrude upward from the cover plate 21. Moreover, the first loose insertion hole 2 is provided on the lower surface of the cover plate 21.
A communication groove 21c communicating with 1a is cut,
The air passing through the communication groove 21c is configured to be discharged only from the first loose insertion hole 21a.

On the other hand, a first air hole 17b communicating with the communication groove 21c and a second air hole 17c orthogonal thereto are bored in the workbench 17, and a hose joint is provided at one end of the second air hole 17c. A hose 23 is connected via 22. This hose 2
3 is connected to an air control circuit 24 to be described later, and air from an air supply source 25 passes through the first air hole 17b, second air hole 17c, communication groove 21c, and first loose insertion hole 21a from the hose 23 to the outside. It is configured to be discharged.

As shown in FIG. 3, the air control circuit 24 has a switching valve 26 that is operated by a screw tightening operation start signal and a screw tightening completion signal. This switching valve 26 is configured to switch the direction of air supply to the first supply/discharge port 8b and second supply/discharge port 8c of the cylinder 8, and the air discharged from the first supply/discharge port 8b is Air is supplied from the hose 23 to the second air hole 17c via a throttle valve 27 and a check valve 28.

In the workpiece positioning device for the stationary screw tightening machine, the workpiece 14 is positioned such that the small diameter portion 18a of the pilot pin 18 is inserted into the prepared hole of the predetermined workpiece 14.
is placed and held from below with a hit pin 20. In this state, when the screw tightening work start signal of the stationary screw tightening machine 1 is input, the switching valve 26 is activated.
Air is supplied from the air supply source 25 to the first supply/discharge port 8b of the cylinder 8. The driver bit 12 is lowered by the operation of the cylinder 8, and the chuck pawl 13a
The screw A held in is released from the chuck pawl 13a. Therefore, the leg of the screw A comes into contact with the pilot pin 18 and lowers it into the workbench 17. At the same time, the leg of the screw A is guided into the prepared hole of the workpiece 14, and is screwed into the prepared hole of the workpiece 14 as the driver bit 12 rotates.

On the other hand, as the switching valve 26 operates, the cylinder 8 operates and air is supplied to the first supply/discharge port 8b, and at the same time, the air that has passed through the throttle valve 27 and the check valve 28 passes through the hose 23 to the 2 air hole 17c. This air passes through the first air hole 17b and the communication groove 21c and is blown upward from the gap between the first loose insertion hole 21a and the pilot pin 18. Therefore, even if chips are generated when the screw A is screwed into the workpiece 14, the chips are removed from the first loose insertion hole 21.
Since the gap between the pilot pin 18 and the pilot pin 18 will not become clogged, the pilot pin 18 will rise to the specified position without any problem during the next screw tightening operation.
After that, it can be lowered and screw tightening work can be continued.

[Effect of idea]

As explained above, in the present invention, a lowerable pilot pin is arranged on a workbench, a cover plate is fixed so that the pilot pin is loosely inserted into the upper surface of the workbench, and the pilot pin is inserted from the gap between the cover plate and the pilot pin. Since it is configured to blow air up, even if chips are generated when screwing a screw into a workpiece, these chips will not get caught in the gap and will be removed by the pilot the next time the screw is tightened. There are advantages such as the ability to reliably lower the pin into the workbench and perform predetermined screw tightening work.

[Brief explanation of the drawing]

Figure 1 is an overall explanatory diagram with the main parts of the invention cut away.
FIG. 2 is an enlarged sectional view of a main part of the present invention, FIG. 3 is an air control circuit diagram according to the present invention, and FIG. 4 is a sectional view of a main part of a conventional example. A...screw, 1...stationary screw tightening machine, 2...
Support, 3...Bracket, 4...Arm, 5...Guide shaft, 6...Chick stand, 7...Driver stand, 8...Cylinder, 8a...Rod, 8b...
...First supply/discharge port, 8c...Second supply/discharge port, 9...Stopper, 10...Motor, 10a...Drive shaft, 11
...Rotation transmission mechanism, 12...Driver bit, 1
3...Chuck unit, 13a...Chuck claw, 14...Work, 15...Work positioning device, 16...Table, 17...Workbench, 17a
...Stepped hole, 17b...First air hole, 17c...
Second air hole, 18...Pilot pin, 18a...
...Small diameter part, 18b...Brim part, 19...Spring, 20
... Hit pin, 21 ... Cover plate, 21
a...First loose insertion hole, 21b...Second loose insertion hole, 21
c...Communication groove, 22...Hose joint, 23
... Hose, 24 ... Air control device, 25 ... Air supply source, 26 ... Switching valve, 27 ... Throttle valve, 2
8...Check valve.

Claims (1)

[Claims for Utility Model Registration] A driver stand 7 that moves up and down by the operation of a cylinder 8 fixed to a bracket 3, and this driver stand 7.
and a drive shaft 10a of the motor 10 that moves up and down integrally with the driver stand 7.
A stationary screw tightening machine having a driver bit 12 that rotates in response to the rotation of the screwdriver bit is disposed, a work table 17 is fixed below the driver bit 12, and the driver bit 1 is fixed on the work table 17.
A pilot pin 18 that extends along the axis of the workpiece 2 and passes through the pilot hole of the predetermined workpiece 14 is biased upward by a spring 19 and placed, and the pilot pin 18 can be loosely inserted into the upper surface of the workbench 17. A cover plate 21 having a first loose insertion hole 21a is fixed, and the first
While cutting a communication groove 21c that communicates with the loose insertion hole 21a, an air hole that communicates with the communication groove 21c is bored in the workbench 17, and air from the air supply source 25 is supplied to one end of this air hole. A workpiece positioning device characterized in that an air control circuit 24 is connected to the workpiece positioning device.